An RF circuit device using modified lattice, lattice, and ladder circuit topologies. The devices can include four resonator devices and four shunt resonator devices. In the ladder topology, the resonator devices are connected in series from an input port to an output port while shunt resonator devices are coupled the nodes between the resonator devices. In the lattice topology, a top and a bottom serial configurations each includes a pair of resonator devices that are coupled to differential input and output ports. A pair of shunt resonators is cross-coupled between each pair of a top serial configuration resonator and a bottom serial configuration resonator. The modified lattice topology adds baluns or inductor devices between top and bottom nodes of the top and bottom serial configurations of the lattice configuration. These topologies may be applied using single crystal or polycrystalline bulk acoustic wave (BAW) resonators.

A filter device includes a filter substrate and a ladder filter at the filter substrate. The ladder filter includes at least one inductor and acoustic wave resonators including a series arm resonator and a parallel arm resonator. The at least one inductor is coupled to the acoustic wave resonators. A pass bandwidth of the ladder filter is larger than a resonance bandwidth of at least one of the acoustic wave resonators. The series arm resonator includes a first piezoelectric substrate. The parallel arm resonator includes a second piezoelectric substrate that is different from the first piezoelectric substrate.

A bandpass filter is provided, comprising a series resonator circuit disposed between an input and an output of the bandpass filter; a first shunt resonator circuit connected to ground in parallel with the series resonator circuit; and a second shunt resonator circuit connected to ground in parallel with the series resonator circuit, the second shunt resonator circuit configured to have one or more frequency pairs comprising an antiresonant frequency and a first resonant frequency, wherein for each frequency pair the antiresonant frequency is within a passband of the bandpass filter and the first resonant frequency at a higher frequency than the antiresonant frequency. A radiofrequency module and a wireless device comprising the same are also provided.

An acoustic wave device includes an interdigital transducer electrode provided on a piezoelectric substrate, the interdigital transducer electrode includes first and second electrode fingers. The second electrode fingers are connected to an electric potential different from that of the first electrode fingers. A direction orthogonal or substantially orthogonal to a direction in which the first electrode fingers and the second electrode fingers extend is an acoustic wave propagation direction, the interdigital transducer electrode includes a first area centrally provided in the acoustic wave propagation direction, second areas provided on one side and another side of the first area in the acoustic wave propagation direction, and third areas each provided on a side of each of the second areas opposite to the first area in the acoustic wave propagation direction.

A filter device includes a first path, a second path, and a capacitor. The first path includes at least one ladder filter circuit and connects a first terminal and a second terminal. The at least one ladder filter circuit includes a parallel arm resonator connected to a ground terminal. The second path includes a grounded resonator and is connected in parallel with any of the at least one ladder filter circuit. One end of the capacitor is connected to the second path, and the other end of the capacitor is connected to a third path which connects the parallel arm resonator and the ground terminal.

A radio-frequency circuit includes a first switch, a first filter, a second filter, a third filter, and a fourth filter. The first switch is capable of selectively connecting a first selection terminal or a second selection terminal to a first common terminal. The first filter and the second filter are connected to the first selection terminal. The third filter and the fourth filter are connected to the second selection terminal. The first filter and the third filter are band pass filters. The second filter is a band elimination filter. A pass band of the first filter and a rejection band of the second filter overlap each other. The pass band of the first filter and a pass band of the third filter overlap each other.

An acoustic wave filter assembly having reduced on-die capacitance and improved isolation for high-frequency applications. The acoustic wave filter assembly includes a filter port, an antenna port, an acoustic wave filter connected between the filter port and the antenna port, one or more ground pins connected between the filter port and the antenna port, and a metallic guard ring extending around the acoustic wave filter assembly. At least one of the one or more ground pins is connected to the metallic guard ring. A diplexer, multiplexer, radio-frequency module and wireless device are also provided.

A high-frequency circuit includes a signal wire connecting a pair of signal terminals; and a reference potential wire arranged along and close to the signal wire and connecting a pair of reference potential terminals.

Aspects of this disclosure relate to a multiplexer with a hybrid acoustic passive filter. The multiplexer includes a plurality of filters configured to filter respective radio frequency signals, a shared filter coupled between each of the plurality of filters and a common node, and a radio frequency filter coupled to the common node. At least a first filter of the plurality of filters includes acoustic resonators and a non-acoustic passive component. Related multiplexers, wireless communication devices, and methods are disclosed.

A hybrid filter device (1) includes an acoustic wave device (AD) that includes an acoustic wave resonator and a passive device (PD) that includes an inductor element or an inductor element and a capacitance element. At least one of the acoustic wave device (AD) and the passive device (PD) is mounted on a substrate (20) of the hybrid filter device (1) and the acoustic wave device (AD) and the passive device (PD) are electrically connected to each other. The acoustic wave device (AD) overlaps the passive device (PD) when the hybrid filter device (1) is viewed in a direction perpendicular to one main surface (20a) of the substrate (20).